First of all: You don't known how much i am happy to see my content on a video in internet. It's like a dream come true for me. I am not kidding, really thank you for that.
Second of all: For the spike with star, this was just a platform for say : "Don't go here, it's dangerous.". I added the star for cosmetic thing. 'Same for the 1-Up and the spring on the last level. I like do thing that serve to nothing but make the game more "alive". So there is you answer. (Also you didn't find the little secret on the first level. But it's not mind-blowing, it's just give you one 1-UP and some piece. But it's always nice to find.)
Anyway, i am going to bed right now. Thank's for play my level and i hope that you will play my futur level! See you next time!